This invention relates to a process and apparatus for minimizing rejections by document processing equipment when using correction stickers to correct incorrectly printed MICR data on documents.
In the check processing industry, for example, checks and other financial documents have intelligence data printed thereon in magnetic ink. The intelligence data relates to bank number, account number, transaction codes, and monetary amount, for example, and this data is referred to as MICR data.
In order to read the MICR data, the document with the MICR data thereon is moved in operative relationship with a magnetic read head. Generally, there are two types of read heads used. The first type is referred to as a "deep" MICR reader, and the cons a "shallow" or "matrix" read head.
The deep MICR reader referred to is a single channel read head for spanning the vertical height of the associated MICR clear band as the MICR characters on a document are moved in a horizontal direction, for example, past the reader. As a typical illustration, such a read head may have a relatively wide gap (about 0.002 inch) and may be able to detect flux changes of the magnetized MICR ink up to a distance of 0.010 inch from the read head.
In contrast, a shallow or matrix read head may have 30 channels or tracks in the head spanning the MICR band, with six or seven of the tracks being exposed to the vertical height of the character being read. Each of the tracks has an individual read head element with a very small head gap therein which can detect flux changes for only a very short distance from the read head. Matrix read heads are much more expensive than deep read heads.
When errors are made in entering the monetary amounts on checks on a proof encoding machine, for example, the procedure used for correcting the errors is generally dependent upon the particular type of reader used for subsequent data capture.
When a shallow reader of the type described is used, a correction sticker is used, commonly, in the error correction process. The correction sticker generally is made of white paper (often with foil backing), has adhesive on one side thereof, and is generally about 7/16.times.13/4 inches in size. In correcting the monetary amount encoded in MICR ink on a document or check, the correction sticker is applied to the check to cover the incorrect monetary amount thereon, and thereafter, the check is processed by an encoder, for example, to have the correct monetary amount encoded or printed on the correction sticker.
The correction sticker generally works well with shallow readers because these readers do not "read through" the correction sticker to be influenced by the incorrect MICR data appearing on the document underneath the sticker; the shallow readers are relatively immune from rejects from this cause. In other words, the shallow readers read only the correct MICR data which appears on the top of the correction sticker.
The shallow readers, however, are not without problems. For example, when MICR data is printed on a document, a "cavity" is produced on the front side of the document due to the printing, and, correspondingly, an embossment is produced on the back side of the document. The MICR ink for the character being printed is deposited in the cavity on the front side of the document. Because the MICR ink for a character lies in the cavity, the shallow read head may not be close enough to the MICR ink, and consequently, a reject may occur. The shallow readers, however, tend to read only the MICR data printed or encoded on the correction sticker.
In contrast, the deep readers tend to read the correct MICR data on the correction sticker and also tend to be influenced by the incorrect MICR data on the document underneath, and consequently, both the correct MICR data on the correction sticker and the incorrect MICR data on the document are "read", causing the document to be rejected as improperly read. The ensuing extra processing and correction procedures are time consuming and expensive for financial institutions, for example.
In an attempt to generally improve correction stickers and to overcome the problem mentioned in the previous paragraph with regard to deep readers and correction stickers, the correction stickers have been redesigned by current suppliers in the industry to include a backing of aluminum foil. Unfortunately, reject rates of up to 90% still persist on deep readers when using the foil-backed stickers. Also, when the correction stickers are made thicker to move the incorrect data on the check out of the range of the deep reader, the thicker correction stickers cause document transport jams, and consequently, are not used.
Today, the common industry approach to solving the correction procedure with deep readers is to use a liquid solvent eradicator for corrections. The eradicator works to remove the magnetic ink associated with the incorrect amount or entry on the document. However, even when the eradicator removes all but a trace of the unwanted MICR ink, as seen by the human eye, for example, there is still a reject rate of about 25 to 30 percent when the correct MICR data is encoded over the eradicated area. This is due to a remanent signal coming from the MICR ink remaining on the document. Also, the use of certain of the liquid solvent eradicators is considered a health hazard by some people. Some countries ban the use of such eradicators.